International Business Machines Corporation

Other

Peter William Cook

Stanley Everett Schuster

Pradip Bose

Hans Mikael Jacobson

Prabhakar Nandavar Kudva

Philip George Emma

Alper Buyuktosunoglu

Robert K Montoye

David M Brooks

Michael K Gschwind

Rajiv V Joshi

Vijayalakshmi Srinivasan

Phillip John Restle

Ching-Te Kent Chuang

Jude A Rivers

Daniel Lawrence Stasiak

Victor V Zyuban

Richard B Brown

Andrew Douglas Davies

Koushik Kumar Das

Lewis M Terman

David H Albonesi

Chih-Liang Chen

Glen S Miranker

Hung-Hui Hsieh

Daniel M Citron

James Thomas Parrish

A method and structure of reducing power consumption in a microprocessor includes at least one storage structure in which the activity of the storage structure is dynamically measured and the size of the structure is controlled based on the activity. The storage structure includes a plurality of blocks, and the size of the structure is controlled in units of block size, based on activity measured in the blocks. An exemplary embodiment is an adaptive out-of-order queue.

Adaptive issue queue for reduced power at high performance

An integrated circuit including a pipeline and a method of operating the pipeline. Each stage of the pipeline is triggered by one or more triggering events and are individually, and selectively, stalled by a stall signal. For each stage a stall signal, delayed with respect to the stall signal of a downstream stage, is generated and used to select whether the pipeline stage in question is triggered. A data valid signal propagating with valid data adds further selection, such that only stages with valid data are stalled.

Interlocked synchronous pipeline clock gating

A method of operating an integrated circuit including a pipeline and a method of stalling stages in the pipeline. Each stage of the pipeline is triggered by one or more triggering events and are individually, and selectively, stalled by a stall signal. For each stage a stall signal, delayed with respect to the stall signal of a downstream stage, is generated and used to select whether the pipeline stage in question is triggered. A data valid signal propagating with valid data adds further selection, such that only stages with valid data are stalled.

Method of stalling one or more stages in an interlocked synchronous pipeline

An integrated circuit (IC) including unit power control, leakage reduction circuit for controllably reducing leakage power with reduced LdI/dt noise in the IC and, an activity prediction unit invoking active/dormant states in IC units. The prediction unit determines turn on and turn off times for each IC unit. The prediction unit controls a supply voltage select circuit selectively passing a supply voltage to a separate supply line at the predicted turn on time and selectively blocking the supply voltage at the predicted turn off time.

Processor with low overhead predictive supply voltage gating for leakage power reduction

A synchronous integrated circuit such as a scalar processor or superscalar processor. Circuit components or units are clocked by and synchronized to a common system clock. At least two of the clocked units include multiple register stages, e.g., pipeline stages. A local clock generator in each clocked unit combines the common system clock and stall status from one or more other units to adjust register clock frequency up or down.

Processor with demand-driven clock throttling power reduction

A multi-threshold integrated circuit (IC) with reduced subthreshold leakage and method of reducing leakage. Selectable supply switching devices (NFETs and/or PFETs) between a logic circuit and supply connections (Vand Ground) for the circuit have higher thresholds than normal circuit devices. Some devices may have thresholds lowered when the supply switching devices are on. Header/footer devices with further higher threshold voltages and widths may be used to further increase off resistance and maintain/reduce on resistance. Alternatively, high threshold devices may be stacked to further reduce leakage to a point achieved for an even higher threshold. Intermediate supply connects at the devices may have decoupling capacitance and devices may be tapered for optimum stack height and an optimum taper ratio to minimize circuit leakage and circuit delay.

Method of reducing leakage current in sub one volt SOI circuits

Leakage current control devices include a circuit having one or more functions in a data path where the functions are executed in a sequence. Each of the functions has power reduction logic to energize each respective function. A leakage control circuit interacts with the power reduction logic, so that the functions are energized or deenergized in a control sequence such that the functions where the data is resident are energized and at least one of the other functions is not energized.

Method and structure for short range leakage control in pipelined circuits

An apparatus and method for externally managing data within an asynchronous pipeline. The asynchronous pipeline over which control is sought includes a data path and a control path. In accordance with the method of the present invention, a data tag value is assigned to the data prior to its entry into the asynchronous pipeline. The data tag value is sent into the control path at the same time the data is sent into its data path such that the data tag value passes through the asynchronous pipeline in parallel with the data to which it is assigned. At a given stage within the asynchronous pipeline, the data tag value is compared with a control tag value, and only in response to the data tag value matching the control tag value is the data permitted to pass to the next stage within the asynchronous pipeline.

Asynchronous pipeline control interface using tag values to control passing data through successive pipeline stages

An interface between synchronous and asynchronous data transfer includes a plurality of stages coupled to each other to form a pipeline for data transfer. The plurality of stages include a first stage which performs synchronous to asynchronous data transfer, at least one intermediate stage which performs asynchronous to asynchronous data transfer and a last stage which performs asynchronous to synchronous data transfer. A synchronous clock path propagates a timing signal across the plurality of stages to enable the first and last stages to perform operations when the timing signal is present at that stage.

Synchronous to asynchronous to synchronous interface

Circuits and methods for operating a latch structure are disclosed. The circuits include a plurality of stages, and each stage includes a first logic circuit, a latch coupled to a second logic circuit of an adjacent stage and a switch which connects the first logic circuit to the latch in a first state and disconnects the logic circuit from the latch in a second state. A local clock circuit controls the first and second states by providing a locally generated clock signal to activate the switch. The locally generated clock signals are generated by interlocking handshake signals from a local clock circuit of an adjacent stage.

Latch structure for interlocked pipelined CMOS (IPCMOS) circuits

A method is provided for associating an address with data. The method includes precharging a matchline connected to a plurality of tag match functions to a first potential, wherein each tag match function comprises one or more match logic devices, discharging two tag lines for a first tag bit to ground, and reading a plurality of tag bits and corresponding data bits onto a plurality of tag lines and a plurality of data lines respectively. The method further includes determining a match between the tag bits and data bits, and pulling the matchline to a second potential upon determining a match for each of the tag bits.

Low-power circuit structures and methods for content addressable memories and random access memories

A method is provided for selecting a participant to issue. The method includes signaling a domino OR gate arbitration device upon a ready request of a participant having a priority, determining within the domino OR gate arbitration device the relative priority of the participant, signaling the domino OR gate arbitration device through an any-request device upon the ready request of a higher priority participant, and issuing the higher priority participant upon determining the higher priority participant to have a priority highest among participants ready for issue. The method includes gating one of a precharge signal and an evaluate signal of the precharged domino OR gate arbitration device by the ready request of the participant. The method further includes latching a result of the domino OR gate arbitration device and a clock signal, and gating the clock signal by the ready signal of the participant.

Circuit structures and methods for high-speed low-power select arbitration

An interlocked pipelined CMOS (IPCMOS) family of logic circuits provides extremely high performance pipelined operation and guarantees error free operation where variations in timing are compensated for automatically by the circuits. The IPCMOS logic circuits also provide a standard interface that makes it possible to interface different macro types easily. The IPCMOS logic circuits feature interlocking in both the forward and reverse directions. This &ldquo;handshaking&rdquo; guarantees error free timing and makes it possible to eliminate the need for a global clock at the macro level. Timing signals are generated locally at the macro level from the handshaking signals between macros. This makes it possible for the local circuits to deal with global timing variations caused by power supply noise, ACLV, and parameter variations. The macros operate in a pipelined mode with data advancing automatically from macro to macro with the timing controlled by the local handshaking signals. This pipelined operation results in an extremely fast cycle time. Another feature of IPCMOS is that the data inputs to a macro are only sampled when the data is in a valid state. making the concept of a standard macro interface possible. With this standard interface, different logic types such as static and dynamic circuits can be easily interconnected and the concept of reusable macros becomes a reality.

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Mount Kisco, NY, United States of America

Peter William Cook